The Guinness World Records, receives 60,000 applications a year from around the globe to break or set a new record. Not all are accepted as some are too dangerous, not enough of a challenge, too specific to an individual, or unbreakable. Only 4,000 records are published in the book each year.
(Interestingly a number of high-profile records are broken on a regular basis. According to Guinness, the most popular include oldest living person, highest grossing film and fastest selling record.)